Technical Field
The present disclosure relates to a process for manufacturing a nozzle plate and a fluid-ejection device comprising said nozzle plate.
Description of the Related Art
Devices for ejecting liquids or, in general, fluids in the form of drops (such as for example inhalers, printing heads, etc.) generally comprise a nozzle plate set facing a reservoir containing the liquid to be ejected. An actuation element, for example a piezoelectric element, can be used for deforming the reservoir and causing exit of the liquid through the nozzles of the membrane. Another known technology for ejecting liquid is thermal technology (known as thermal inkjet or bubble inkjet), where a heater, set between each nozzle and the reservoir, is configured to generate a bubble of vapor that causes ejection of liquid from the respective nozzle.
It is clear that, irrespective of the ejection technology used, the size and shape of the nozzles, as well as the uniformity of size and shape of the nozzles, are particularly important parameters for defining the size and directionality of the drops generated and their reproducibility.
Generally, the nozzles have a cylindrical shape with an outlet diameter smaller than the diameter of the channel that supplies the nozzles with the liquid to be ejected. Frequently, between the supply channel and the respective nozzle, a substantially frustoconical connection element is moreover provided having a major-base section (with a diameter equal to the diameter of the supply channel) coupled to the supply channel itself, and a minor-base section (with a diameter equal to the diameter of the base section of the nozzle) coupled to the nozzle. This configuration enables an increase in the speed of ejection the drops generated. However, the coupling step, in particular between the connection element and the nozzle, is not easy, and is frequently the cause of undesirable misalignments.
In addition, nozzles having an outlet mouth that protrudes from the nozzle plate are particularly subject to damage, and to the undesirable deposit of material that is likely to create an obstacle to ejection of the liquid. A further disadvantage of said nozzle plates is the dependence of the drop ejected upon the outer structural conformation of the nozzles.